<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Faisal peer mohamed</style></author><author><style face="normal" font="default" size="100%">W H Siew</style></author><author><style face="normal" font="default" size="100%">John J. Soraghan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">High Frequency Modelling of Protection-Measurement Current Transformers for Partial Discharge Detection</style></title><secondary-title><style face="normal" font="default" size="100%">Proceedings of the 44th International Universities Power Engineering Conference</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">High Voltage Engineering and Dielectrics</style></keyword><keyword><style  face="normal" font="default" size="100%">HV Modelling &amp; Design</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">September</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%"></style></number><edition><style face="normal" font="default" size="100%"></style></edition><publisher><style face="normal" font="default" size="100%"></style></publisher><pub-location><style face="normal" font="default" size="100%">University of Strathclyde</style></pub-location><volume><style face="normal" font="default" size="100%"></style></volume><pages><style face="normal" font="default" size="100%"></style></pages><isbn><style face="normal" font="default" size="100%"></style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Most of the high voltage systems comprising electricity generation, transmission and distribution infrastructure in the UK are approaching the end of its predicted life. Immediate and wholesale replacement of these assets is difficult. In these circumstances informed maintenance planning through on-line condition monitoring gives much relief by avoiding unplanned outages. High voltage insulation is an important part of a power plant that degrades by aging due to mechanical, electrical and thermal stresses. Insulation failure can lead to catastrophic failure of an equipment with serious hazards including health and safety, environmental and economic consequences. It is necessary that degradation of such systems be monitored at an early stage, so that appropriate replacement and repair can be arranged at the appropriate time. Partial discharge (PD) detection is an effective diagnostic tool for insulation degradation in high voltage equipments. Traditionally, cable diagnostics were carried out using offline methods, whereby the cables are removed from service and tested for partial discharges. On the other hand, online PD diagnostics are preferable since no outages are required. This paper is focussed on the on-line PD detection in medium voltage cables. PD signals in these cables propagate via two possible channels namely shield - phase and phase-phase. Traditionally, high frequency current transformers (HFCT) which are installed in the earth strap of cables are used to detect these high frequency PD signals. Often earth strap accessibility is limited due to the substation design. Moreover PD signals obtained from earth straps are not ideal for signal processing. In this case phase-phase measurement is the other alternative. On-line installation of these sensors are difficult since sensor installation in live phase conductors is always not possible . In order to overcome this difficulty, it is logical that one should consider using the preinstalled protection and measurement CTs for detecting PD signals. However, the frequency response of such CTs is not normally available because they are not quantified by any manufacturer. This paper therefore investigates the suitability of preinstalled protection and measurement CT for detecting high frequency PD signals in medium voltage cables by conducting frequency response analysis (FRA) of these CTs and by frequency response modelling. Many high frequency models have been developed by researchers and most of the models were developed for the transient behaviour of CTs. Energy of the high frequency signals in those models is very high. As far as PD is concerned, the energy content is very low. Transformer core behaviour will be different in both cases and, as far as the authors could ascertain, there is little information on the FRA of such CTs for low energy high frequency input. This is addressed in the proposed paper, which presents a high frequency model of such current transformers for low energy high frequency signals. Model parameters such as parasitic capacitances, leakage inductance, winding resistance, and iron loss component were obtained from the frequency response analysis experiments. Simulation and experimental results will be compared.</style></abstract><issue><style face="normal" font="default" size="100%"></style></issue><work-type><style face="normal" font="default" size="100%"></style></work-type><accession-num><style face="normal" font="default" size="100%"></style></accession-num><call-num><style face="normal" font="default" size="100%"></style></call-num><notes><style face="normal" font="default" size="100%"></style></notes><custom1><style face="normal" font="default" size="100%"></style></custom1><custom2><style face="normal" font="default" size="100%"></style></custom2><custom3><style face="normal" font="default" size="100%"></style></custom3><custom4><style face="normal" font="default" size="100%"></style></custom4><custom5><style face="normal" font="default" size="100%"></style></custom5><custom6><style face="normal" font="default" size="100%"></style></custom6><custom7><style face="normal" font="default" size="100%"></style></custom7><research-notes><style face="normal" font="default" size="100%"></style></research-notes><num-vols><style face="normal" font="default" size="100%"></style></num-vols><orig-pub><style face="normal" font="default" size="100%"></style></orig-pub><reprint-edition><style face="normal" font="default" size="100%"></style></reprint-edition><section><style face="normal" font="default" size="100%"></style></section><auth-address><style face="normal" font="default" size="100%"></style></auth-address><remote-database-name><style face="normal" font="default" size="100%"></style></remote-database-name><remote-database-provider><style face="normal" font="default" size="100%"></style></remote-database-provider><label><style face="normal" font="default" size="100%"></style></label><access-date><style face="normal" font="default" size="100%"></style></access-date></record></records></xml>
